Chapter 1. Installing Pipe Nozzles
14
T5 Flare Gas Transducer Installation Guide
1.2.7 Hot Tapping the Pipe
1.2.7a Hot Tapping For 3” Flanges
To hot tap the pipe for 3” flanges, complete the following steps:
1.
Obtain two suitable 3 in. ANSI flanged isolation valves. The valves should be a full bore type with either
150# RF flanges and a face-to-face length of 8 in. or 300# RF flanges and a face-to-face length of 11.125 in.
2.
Install one of the isolation valves, including a suitable gasket, on each of the nozzles. Secure the valves with
either 5/8 in. studs and nuts for 150# flanges or 3/4 in. studs and nuts for 300# flanges.
3.
Orient the isolation valve handles to minimize interference during operation of the valves.
4.
Hot tap holes in the pipe using a hot tap machine equipped with a 3/4 in. (19.05 mm) drill bit.
5.
Then use a coupon retaining hole saw to cut a hole with a diameter of 2.36 in. (60 mm) minimum to
2.875 in. (73 mm) maximum.
1.2.7b Hot Tapping For 2” Flanges
To hot tap the pipe for 2” flanges, complete the following steps:
1.
Obtain two suitable 2 in. ANSI flanged isolation valves. The valves should be a full bore type with either
150# RF flanges and a face-to-face length of 7 in. or 300# RF flanges and a face-to-face length of 8.50 in.
2.
Install one of the isolation valves, including a suitable gasket, on each of the nozzles. Secure the valves with
5/8 in. studs and nuts.
3.
Orient the isolation valve handles to minimize interference during operation of the valves.
4.
Hot tap holes in the pipe using a hot tap machine equipped with a 3/4 in. (19.05 mm) drill bit.
5.
Then use a coupon retaining hole saw to cut a hole with a diameter of 1.81 in. (46 mm) minimum to
1.89 in. (48 mm) maximum.
1.2.8 Cold Tapping the Pipe
The procedure for cold tapping a pipe is the same as the hot tapping procedure described above. However, isolation
valves are not necessary during the tapping process. The hot tap machine is used directly on the nozzles. The isolation
valves are added after the tapping process has been completed.
WARNING!
Hot tapping should only be performed by qualified personnel. Follow all applicable code
and safety practices during these procedures.
WARNING!
Cold tapping should only be performed by qualified personnel. Follow all applicable code
and safety practices during these procedures.
